Patent Literature 1 discloses that, in an image processing device, a brightness distribution of an image is determined from a histogram of the number of pixels having component values for the brightness of an image indicated by image data, one of a plurality of gradation correction conditions is selected based on the determination, and the selected gradation correction condition is used to correct the component of the brightness.
Patent Literature 2 discloses that a histogram of a black-and-white multi-value image is created, a peak of the brightness of the black-and-white multi-value image is detected, and, based thereon, a brightness averaging conversion table or a brightness conversion table of the black-and-white multi-value image is used for conversion.
Patent Literature 3 discloses that it is determined whether or not an image is a night scene photography based on the feature of the entire image data, a subject is determined based on the feature of high brightness pixels in the image data, and gradation correction to the night scene photography is changed based on the determination of the subject.